Where next with the science of ocean acidification?

Wed, 08 Jun 2016

How will ocean acidification affect fisheries around the world as carbon dioxide levels rise? This question is among the research priorities identified by leading scientists in a new report authored by IUCN experts.

Ocean acidification spells bad news for shellfish as corrosive water can eat away at shells as they form.

Photo: Nelson Suarez

Research shows that rising levels of dissolved carbon dioxide cause ocean acidification, which is expected to harm many marine species, but much remains unknown.

Which regions will be most affected, how quickly species will adapt, and how ecosystems will react to ocean acidification combined with other stresses such as pollution, warming and over-exploitation are on the research priority list identified in the report, Where next with the science of ocean acidification?Another urgent question is how these impacts will in turn affect fisheries and other ‘ecosystem services’ the oceans provide us with.

The oceans are now 30% more acidic than before the industrial revolution, and continued acidification could seriously affect marine life, especially shellfish, corals and plankton.

“Acidification is progressing at unprecedented rates, and we are already seeing the impacts on ecosystems and industries such as aquaculture,” says Carl Gustaf Lundin, Director of IUCN’s Global Marine and Polar Programme.

This is the case in the Pacific Northwest, for instance, where oyster larvae mortality has been linked to the acidity of the water.

The effects on fisheries could have repercussions on food security. Polar and sub-polar regions – important fishing grounds – are particularly vulnerable to acidification, as carbon dioxide absorbs more readily in cold water.

Another ‘ecosystem service’ provided by the oceans is the oxygen pumped out by plankton, equivalent to roughly half of the earth’s oxygen. With ocean acidification thought to affect plankton, it could also have an impact on oxygen production.

To make sure research is translated into action, data on water acidity and the effects of ocean acidification must be global, the researchers say:

“At present material used to illustrate effects of ocean acidification to inform policy makers or drive action on addressing this issue are being drawn from too few examples,” according to the report.